So, the question came up during the making of a swordsage, and the need to check if the maneuvers chosen can actually be acquired due to prerequisites.

Is there anything, in pdf or online form, that has the maneuvers organised in a reasonable way, one that does not give you headaches for just trying to find a meneuver? I have the book and the maneuver cards, but they are still somehow troublesome to the brain.

This Unofficial Tome of Battle Tools page contains a search engine for all maneuvers in the Tome of Battle. "Number of prerequisites" is one of the possible filters. Full maneuver texts are accessible.